Can Citrus Really Help Your God-Awful Allergies?

It's that time again. My eyes are swelling to extraterrestrial proportions, and the lower quadrant of my sweet, sweet face is marred by a constant post-nasal drip. It's allergy season, baby, and I always forget just how miserable it is. Of course, I've been feeding myself a steady diet of Zyrtec every day for the last four years—but what if there was a cheaper, more natural way to stave off my allergies? What if I could simply eat...oranges?

I've heard of orange juice as a cure for the common cold, but I've always brushed that off as an old wives' tale. Sure, vitamin C is said to support immune function; still, I've never been convinced of the healing powers of a cup of Tropicana. But recently, I found myself trawling the internet for foods that could ease the effects of allergy season. Vitamin C popped up time and time again as researchers argued that foods rich in vitamin C—things like oranges, peppers, and broccoli—have naturally anti-inflammatory effects.

At first glance, the evidence looks pretty good. A quick search resulted in the following studies:

• STUDY A: In this review, researchers assessed pre-published data and found "promising evidence" that vitamin C could decrease inflammation and swelling associated with allergic reactions.
• STUDY B: One study of schoolchildren suggests that vitamin C can decrease instances of allergic rhinitis, the irritation of the upper respiratory tract caused by pollen.
• STUDY C: Meanwhile, in this study, researchers found that vitamin C could reduce individual levels of histamines (the chemicals created in the body that cause allergic symptoms like sneezing). To be specific, researchers found that individual histamine levels reduced by about 38% after an individual took two grams of vitamin C.

Alas, there's a catch. Actually, several catches. I'll break these down by studies as well:

• STUDY A: The first study cited above isn't a study at all—it's a review of existing studies. The researchers are said to have found "promising evidence" that vitamin C could decrease inflammation; however, it's unclear exactly which metrics they used to classify the evidence as "promising."
• STUDY B: This study is largely qualitative, which gets especially tricky considering that the subjects are kiddos. The researchers evaluated 4,554 children in Seoul, Korea, asking them to measure their vitamin C intake via a "semi-quantitative food frequency questionnaire." After that, the researchers asked the children a series of questions—for example, "Have you ever had a problem with sneezing or a runny or blocked nose when you did not have a cold or the flu?" That's a pretty general question for a kid to answer with scientific accuracy. In the end, it's doubtful that vitamin C can decrease instances of allergic rhinitis; more likely that the kids who reported fewer instances of rhinitis either didn't report accurately or just coincidentally consume more vitamin C on a regular basis.
• STUDY C: Vitamin C did, indeed, reduce histamines in test subjects. Unfortunately, a single medium navel orange only contains about 0.07 grams of vitamin C. Thus, you'd theoretically have to eat 28 oranges per day to reap the histamine-reducing benefits. You'd probably be better off mainlining straight vitamin C through an IV, like in this study.

Ultimately, eating oranges during allergy season certainly won't hurt anything. They're delicious, and you still have time to catch the tail end of peak citrus season. But if, like me, you suffer from severe allergies, you might have to bring in the big guns to make it through.